EMAIL SPAM is often harmful with malicious website links or downloader agents that install even more software including harmful ransomware agents that can encrypt user files on the computer.  The ISC documents an advanced and harmful new attack as follows:

Dalexis is a malware downloader.  It drops a CAB file with embedded document that’s opened on a user’s computer then downloads more malware.  Dalexis is often used to deliver CTB-Locker.  CTB-Locker is ransomware that encrypts files on your computer.  In exchange for a ransom payment, the malware authors will provide a key to decrypt your files.  Behavior of this malware is well-documented, but small changes often occur as new waves of malspam are sent out.